A 72-year-old man has filed a legal challenge to the requirement that a recipient of old-age allowance live continuously for a year in the city. He says it infringes his right to social welfare and wants a court to declare it unconstitutional.

Lam Wo-lun submitted the application for a judicial review to the High Court on Monday.

Lam, a permanent resident, is asking the court to quash the Director of Social Welfare's decision to reject his application for the allowance because he did not satisfy the continuous residency requirement, and the dismissal of his subsequent appeal.

He also wants the court to declare that the requirement for a year's continuous residency before applying for the allowance violates the Basic Law, the International Covenant on Economic, Social and Cultural Rights and the Bill of Rights, and is therefore unconstitutional and void.

Lam's application was rejected in 2008, after he turned 70, because he had spent too much time on the mainland. So he refrained from travelling, applied again and was accepted in October this year. Born on the mainland, Lam moved to Hong Kong around 1949 and worked for 40 years as a driver and messenger before retiring in 2004 at age 65.

Lawmakers recently called for the government to scrap the residency requirement.

According to figures quoted in the filing, provided by the Social Welfare Department, 2,820 applications for the allowance were rejected and 338 were withdrawn last year because they did not satisfy the one-year residency requirement.

Although Lam has since been approved to receive the allowance, the filing said the court should hear his case, in part because it raises important questions that affect many people in a similar situation.

Under the scheme, to qualify for the allowance an applicant must have lived in Hong Kong continuously for one year - with an absence of 56 days allowed - as well as having qualified for permanent residency by living in the city the for seven years.

If they satisfy those requirements, people aged 65 to 69 with income below prescribed limits are eligible for the normal old-age allowance, and anyone aged above 70 for the higher old-age allowance. The second allowance was previously more than the first, but both are now HK$1,000.